A wrist watch with a solar battery has been well known. In general, the solar battery built in the conventional solar-battery wrist watch is formed in a sheet form and is arranged on a reverse side of a watch face, which is made of a light transmitting material.
In the conventional solar-battery wrist watch, however, there are many limitations to decoration to be made on the watch face of a light transmitting material, because it is necessary in the solar-battery watch to secure a surface on the sheet-shaped solar battery wide enough to receive light. Therefore, it has been noticed that the conventional solar-battery watch is behind in an external view and design, since attractive decoration is hardly made on the watch face because of the limited space on the watch face.
It is an aspect of the present invention to provide a timepiece having the solar battery that is more effective in a light acceptance than the conventional battery, or a timepiece which is more attractive in its external view and design with various decorations on its dial face.
It is another aspect of the present invention to provide a timepiece and an electronic apparatus with the solar battery that generates energy sufficiently without giving limitations on its indication area.
According to an aspect of the present invention, there is provided a timepiece which comprises a casing, a digital face provided in the casing, a time counting module provided in the casing; and a bulb-shaped semiconductor element mounted on the digital face for supplying driving power to the time counting module.
Since the bulb-shaped semiconductor element mounted on the digital face is formed in a bulb shape, the semiconductor element is low in light directivity so that it can receive direct light, reflected light, and/or scattered light from every direction, generating electricity efficiently. The conventional solar battery of a sheet type needs a wide surface for receiving light, restricting a space for decoration on the watch face. On the contrary, since the solar battery used in the present invention has a unique shape such as a bulb-shape, it can be arranged on a recess or a projecting portion or a curved portion of the casing, which allows to decorate the timepiece using the bulb-shaped semiconductor element being arranged on the recess or projecting portion or the curved portion of the casing. Therefore, according to the present invention timepieces which are more attractive in their design and external view are available.
Further, according to another aspect of the invention, there is provided a time piece which comprises a casing, a display section provided in the casing, a protection glass of a light transmittance nature mounted on the casing so as to face the display section: and a solar battery disposed so as to face a peripheral edge of the protection glass.
When the timepiece according to the invention is exposed to the external light, a part of the external light transmits through the protection glass, and reaches the display section, allowing a user to see the display section clearly. In addition, the part of the external light being guided along the protection glass is emitted from the edge of the protection glass against the solar battery. In other words, the battery can efficiently receive the external light taken in through a whole surface of the protection glass and generates electricity. Further the batteries are arranged in the vicinity of the peripheral edge of the protection glass, so that this arrangement of the batteries does not give any restriction to the display section mounted within the casing.
According to still another aspect of the invention, there is provided a timepiece which comprises a casing, a window section provided to the casing, a display member of a light transmittance nature provided in the casing so as to face the window section: and a solar battery arranged so as to face a peripheral edge of the display member.
When the timepiece is exposed to the external light, the external light is allowed to transmit through the window section to illuminate the display member for recognition by a user. A part of the light illuminating the display member is guided in the display member toward the peripheral edge to irradiate the solar battery. The external light is received through a whole surface of the display member and transmitted to the solar battery, allowing the solar battery to generate the electric power sufficiently. The solar battery is disposed to face the peripheral edge of the display member, so that the display member receives no restriction.